I need some advice here!

Last September I began attending a boxercise class. I was expecting it to be tough so I removed the clothes that had been hanging on my exercise bike and finally started using it before going to the boxercise classes. I gradually spent longer and longer on it until I felt I was fit enough to go to boxercise...

Well... The first session nearly killed me, I had to sit out 4 'rounds' and was aching like hell the next day. But I kept going to the classes and started exercising in between and really improved my fitness.

Between the classes, I would do weights, wall sits, planks, squats, lunges as well as intense spells on the exercise bike, usually alternately between pedalling quite fast and then having a sudden burst where I pedalled as fast as I could. I would do 5.5 mins quite fast, 30 second burst, 6 mins quite fast, 30 second burst, 5 mins quite fast, 30 second burst, 5 mins quite fast, 2 minute burst, 3.5 mins quite fast, 1.5 minute burst to bring it up to a total of 30 minutes.

I then got out of the routine of using the exercise bike in March but continued with the weights before getting out the routine for that about 6 weeks ago.

Yesterday I went back on the exercise bike and did 3.5 mins quite fast then a 30 second burst and had to come off!! I couldn't do anymore was wheezing for the next couple of hours!!!!

Does anyone have any suggestions for what I should do next because I know I've been out of the routine for a while but I didn't expect to struggle THAT much!!

Yesterday I only did the exercise bike. Today I did weights as well; single bicep curls, shoulder presses, upright rows, double bicep curls and dumbbell floor presses.

I went on the exercise bike after that - and, like yesterday, I did 3 and a half minutes quite fast followed by a 30 second burst. It wasn't easy but at least I didn't feel like I was having an asthma attack and there was no wheezing either.